Idle speed control apparatus in throttle body

Abstract

An idle speed control apparatus which improves freedom of selection in an opening degree characteristic of a throttle valve is structured such that an intake passage of a throttle body is opened and closed by a throttle valve, a cam lever is attached to one end of a rotatably supported link shaft, a link lever is attached to another end of the link shaft, a slider of a stepping motor is connected to the link lever, a cam portion of the cam lever is connected to a roller of the throttle valve lever, linear motion of the slider is transmitted to the link shaft via the link lever to rotationally displace the link shaft, rotation of the cam lever is transmitted to the throttle valve lever, and the throttle valve opens an idling opening degree corresponding to the rotation of the stepping motor.

Description

FIELD OF THE INVENTIONThe present invention relates to a throttle body used in a fuel injection apparatus which increases a pressure of fuel within a fuel tank by a fuel pump and supplies the pressure increased fuel to an engine via a fuel injection valve, and more particularly to an idle speed control apparatus in a throttle body which controls a low opening degree area of a throttle valve controlling an opening area of an intake passage passing through the throttle body.DESCRIPTION OF THE PRIOR ARTA conventional idle speed control apparatus in a throttle body is shown in FIG. 4.Reference numeral 30 denotes a throttle body provided with an intake passage 31 extending through the inside thereof. A butterfly type throttle valve 33 controlling so as to open and close the intake passage 31 is attached to a throttle valve shaft 32 rotatably supported to the throttle body 30 across the intake passage 31.Reference numeral 34 denotes a main driving lever fixed to the throttle valve shaft 3...

AI Technical Summary

Benefits of technology

An idle speed control apparatus in a throttle body in accordance with the present invention is made by taking the problems mentioned above into consideration, and an object of the present invention is to provide an idle speed control apparatus which can improve a freedom of selection in an opening degree characteristic of a throttle valve, improve a resolving power with respect to an opening degree change of the throttle valve, and reduce an impact against a stepping motor at the time of suddenly closing the throttle valve.

Further, in accordance with the second aspect of the present invention, since the slider and the link lever are clamped by the nut and the collar pressed by the spring, it is possible to freely adjust the position of the slider with respect to the link lever by screwing the nut so as to change the nut position. Further, when the link lever presses the slider in an impact manner at the sudden close time of the throttle valve or the like, the impact force is absorbed by the elastic movement of the collar, so that no great load is applied to the stepping motor.

Further, in accordance with the third aspect of the present invention, since the outer surface of the collar and the inner surface of the link lever are brought into contact with each other in a similar manner to a point contact, it is possible to accurately convert the linear motion of the slider into the rotational motion of the link lever, and a friction on the contact surfaces is less generated, so that it is possible to improve the durability.

Further, in accordance with the fourth aspect of the present invention, since the stepping motor is arranged in the side space formed between the adjacent fuel injection valves, it is possible to well arrange the stepping motor having a comparatively large shape.

Problems solved by technology

Second, it is impossible to effectively improve a resolving power of the opening degree change in the throttle valve 33 with respect to the stroke movement of the slider 43 in the stepping motor M.

Third, it is hard to reduce an impact against the stepping motor M at the sudden closing time of the throttle valve when the throttle valve 33 is suddenly closed from a state opening at a high opening degree to the idling opening degree.

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